<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			#progess{
				height: :30px;
				width: 100%;
				background: gray;
			}
			#bar{
				width: 1%;
				height: 30px;
				background: green;
			}
		</style>
	</head>
	<body>
	<div id="progess">
		<div id="bar"></div>
	</div>
		<button id="btn">点击</button>
		<script>
			var btn=document.getElementById('btn');
			var bar=document.getElementById('bar');
			btn.onclick=function(){
				var timer=setInterval(myfun,30);
				var width=1;
				function myfun(){
					if(width>=100){
						clearInterval(timer);
					}else{
						width=width+3;
						bar.style.width=width+'%'
					}
				}
			}
		</script>
	</body>
</html>
